Dry weeks in early summer have already made 2010 a vintage year for archaeology, English Heritage said yesterday. The conditions allowed hundreds of cropmark sites – created when crops grow at a different rate over buried features – to be seen from the air. A Roman camp near Bradford Abbas, Dorset, was found after three sides appeared in parched barley fields. The lightly built defensive enclosure would have provided basic protection for Roman soldiers while on manoeuvres in the first century AD and is one of only four discovered in the south west of England, English Heritage said.

The dry conditions also allowed well known sites to be photographed in greater detail. Newton Kyme, near Tadcaster, North Yorkshire, was shown to be home not only to a 2,000-year-old Roman fort but also to a larger defence built in AD290. Stone walls up to three metres thick and a ditch 15 metres wide were revealed by an image taken from a Cessna light aircraft.

Dave MacLeod, an English Heritage senior investigator based in York, said: "It's hard to remember a better year.

"Cropmarks are always at their best in dry weather, but the last few summers have been a disappointment.

"This year we have taken full advantage of the conditions. We try to concentrate on areas that in an average year don't produce much archaeology."

"Sorties to the West Midlands and Cumbria, together with more local areas such as the Yorkshire Wolds and Vale of York, have all been very rewarding."

Flights over the Holderness area of the East Riding proved particularly productive with around 60 new sites, mainly prehistoric, found in just one day, including livestock and settlement enclosures.

English Heritage said some sites were visible for the first time since the 1976 drought.